Nasal calcitonin formulations containing chlorobutanol

ABSTRACT

An aqueous solution of calcitonin suitable for intranasal administration comprised of calcitonin, chlorobutanol at a concentration of less than 0.4% weight/weight, and water and having a pH of less than 4 with the proviso that benzalkonium chloride is not present in the solution. The aqueous solution of calcitonin can be used to treat osteoporosis, Paget&#39;s bone disease and hypercalcemia.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.12/878,936, filed on Sep. 9, 2010, which is a continuation of U.S.patent application No. 10/805,788, filed on Mar. 22, 2004, now U.S. Pat.No. 7,812,120, which claims priority of U.S. Provisional PatentApplication No. 60/456,921, filed on Mar. 21, 2003. The entire contentsof these applications are incorporated herein by reference in theirentirety.

BACKGROUND OF THE INVENTION

The teachings of all of the references cited herein are incorporatedherein by reference.

Calcitonin is a polypeptide hormone secreted by the parafollicular cellsof the thyroid gland in mammals and by the ultimobrancial gland of birdsand fish. Synthetic salmon calcitonin is produced and sold by NovartisPharmaceuticals Corporation (East Hanover, N.J.). It is used to treat avariety of conditions including postmenopausal osteoporosis, symptomaticPaget's disease of bone, and hypercalcemia. Calcitonins have beenextracted from a number of sources including salmon, porcine, eel andhuman. Calcitonins with amino acid sequences identical to the naturalforms have been produced by chemical synthesis as well as by recombinanttechnology.

Currently calcitonin is administered either by subcutaneous orintramuscular injections or it is administered intranasally. Intranasaladministration of calcitonin is disclosed in U.S. Pat. No. 5,759,565.The nasal formulation was designed to be stored in a multi-dosecontainer that was stable for an extended period of time and resistedmicrobial contamination. The preservative in the formulation,benzalkonium chloride has been shown to aggravate rhinitis in healthyvolunteers who were given a decongestant nasal spray containing thepreservative, and allergic reactions to the intranasal salmon calcitoninspray MIACALCIN® have been reported, including one of anaphylacticshock. This is believed to be due to the preservative benzalkoniumchloride because the patient could tolerate injectable salmoncalcitonin, which contains no benzalkonium chloride, without incident.See the ‘Physicians Desk Reference’ 2002 edition page 2375 (MedicalEconomics, Montvale, N.Y.). Benzalkonium chloride also has adverse(Hallen, H et. al., Clin. Exp. Allergy25: 401-405 (1995). Also studieshave shown that when respiratory mucosal tissue is exposed tobenzalkonium chloride in vitro, the tissue underwent severemorphological alterations, Berg et al., Larynogoscope, 104:153-1158(1994). Benzalkonium chloride also caused significant slowing of themucocilary transport velocity in the ex vivo frog palate test, Braga, P.C., et al., J. Pharm. Pharmacol. 44:938-940 (1992).

Thus, there is a need for a new formulation of intranasal calcitoninthat contains a preservative other than benzalkonium chloride.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a nasal spray pump/actuator that is not engaged.

FIG. 1B shows the nasal spray pump/actuator that is engaged andexpelling a spray plume.

FIG. 2 shows the spray pattern produced by the actuator wherein 24represents the major axis and 26 represent the minor axis.

DESCRIPTION OF THE INVENTION

The present invention fills this need by providing for an intranasalformulation of calcitonin comprised of calcitonin, preferably salmoncalcitonin, chlorobutanol at a concentration of less than 0.4%weight/weight, and water and having a pH of less than 4 with the provisothat benzalkonium chloride is not present in the formulation. Thepreferred pH of the solution is about between 3 to 4, most preferably3.5. The preferred formulation is comprised of 0.25% weight/weight ofchlorobutanol, 0.85% sodium chloride, 0.0355% calcitonin and 98.86%purified water and the pH is about 3.5.

The prior art teaches away from the use of chlorobutanol stating that at0.6% concentration, the chlorobutanol caused more than 50% inhibition ofciliary beating frequency of rat trachea. However according to thepresent invention, this effect is greatly reduced when the concentrationof chlorobutanol is less than 0.4% and totally eliminated at aconcentration of around 0.25%. The prior art also teaches thatchlorobutanol at 0.6% in calcitonin nasal pharmaceutical compositionsshowed insufficient activity against the test fungus Penicilliumsteckii. However, according to the present invention, it has beendiscovered that chlorobutanol is very effective in inhibiting the growthof Penicillium steckii, when the concentration of chlorobutanol is lessthan 0.4% and the pH of the calcitonin solution is less than 4.

In accordance with the present invention, it has now been surprisinglybeen discovered that an intranasal formulation of calcitonin can beproduced that are stable, inhibit the growth of Penicillium steckii anddo not inhibit the ciliary beating frequency of rat trachea wherein thepreservative used is chlorobutanol at a concentration of less than 0.4%wherein the pH is less than 4.

Accordingly, the present invention provides, in a first aspect, apharmaceutical solution for nasal administration comprising:

i) a calcitonin,

ii) chlorobutanol at a concentration less than 0.4% and

iii) a liquid diluent or carrier suitable for application to the nasalmucosa wherein the pH of the solution is less than 4, with the provisothat the solution does not contain benzalkonium chloride due to theallergic nature of benzalkonium chloride.

The term “calcitonin” is used throughout the present specification andclaims to include not only the natural calcitonins, but also theirpharmaceutically active derivatives and analogues, e.g. in which one ormore of the amino acid residues present in the naturally occurringproduct is replaced, or in which the amino or carboxyl terminus of thepolypeptide is modified. Preferred calcitonins for use in accordancewith the present invention include salmon, human, porcine and eelcalcitonins. All of these calcitonins are commercially available Thecalcitonins for use in the present invention may be in free form or inpharmaceutically acceptable salt or complex form, e.g., inpharmaceutically acceptable acid addition salt form. Such salts andcomplexes are known and possess an equivalent degree of activity andtolerability to the free forms. Suitable acid addition salt forms foruse in accordance with the invention include for example thehydrochlorides and acetates.

The above-described calcitonin solutions are designed to be administeredto the nasal mucosa either in drop or in spray form. However, thepreferred mode of administration is in spray form, i.e., in the form offinely divided droplets. An example of a suitable spray pump is thePfeiffer Spray Pump Model # 63385 produced by Pfeiffer GmbH, Radolfzell,Germany.

Aerosol Nasal Administration of Calcitonin

Calcitonin is administered intranasally using a nasal spray or aerosolaccording to the present invention. In this area the followingdefinitions are useful.

1. Aerosol—A product that is packaged under pressure and containstherapeutically active ingredients that are released upon activation ofan appropriate valve system.

2. Metered aerosol—A pressurized dosage form comprised of metered dosevalves, which allow for the delivery of a uniform quantity of spray uponeach activation.

3. Powder aerosol—A product that is packaged under pressure and containstherapeutically active ingredients in the form of a powder, which arereleased upon activation of an appropriate valve system.

4. Spray aerosol—An aerosol product that utilizes a compressed gas asthe propellant to provide the force necessary to expel the product as awet spray; it generally applicable to solutions of medicinal agents inaqueous solvents.

5. Spray A liquid minutely divided as by a jet of air or steam. Nasalspray drug products contain therapeutically active ingredients dissolvedor suspended in solutions or mixtures of excipients in nonpressurizeddispensers.

6. Metered spray—A non-pressurized dosage form consisting of valves thatallow the dispensing of a specified quantity of spray upon eachactivation.

7. Suspension spray—A liquid preparation containing solid particlesdispersed in a liquid vehicle and in the form of course droplets or asfinely divided solids.

The fluid dynamic characterization of the aerosol spray emitted bymetered nasal spray pumps as a drug delivery device (“DDD”). Spraycharacterization is an integral part of the regulatory submissionsnecessary for Food and Drug Administration (“FDA”) approval of researchand development, quality assurance and stability testing procedures fornew and existing nasal spray pumps.

Thorough characterization of the spray's geometry has been found to bethe best indicator of the overall performance of nasal spray pumps. Inparticular, measurements of the spray's divergence angle (plumegeometry) as it exits the device; the spray's cross-sectionalellipticity, uniformity and particle/droplet distribution (spraypattern); and the time evolution of the developing spray have been foundto be the most representative performance quantities in thecharacterization of a nasal spray pump. During quality assurance andstability testing, plume geometry and spray pattern measurements are keyidentifiers for verifying consistency and conformity with the approveddata criteria for the nasal spray pumps.

Definitions

Plume Height—the measurement from the actuator tip to the point at whichthe plume angle becomes non-linear because of the breakdown of linearflow. Based on a visual examination of digital images, and to establisha measurement point for width that is consistent with the farthestmeasurement point of spray pattern, a height of 30 mm is defined forthis study

Major Axis—the largest chord that can be drawn within the fitted spraypattern that crosses the COMw in base units (mm)

Minor Axis—the smallest chord that can be drawn within the fitted spraypattern that crosses the COMw in base units (mm)

Ellipticity Ratio—the ratio of the major axis to the minor axis

D₁₀—the diameter of droplet for which 10% of the total liquid volume ofsample consists of droplets of a smaller diameter (μm)

D₅₀—the diameter of droplet for which 50% of the total liquid volume ofsample consists of droplets of a smaller diameter (μm), also known asthe mass median diameter

D₉₀—the diameter of droplet for which 90% of the total liquid volume ofsample consists of droplets of a smaller diameter (μm)

Span—measurement of the width of the distribution, The smaller thevalue, the narrower the distribution. Span is calculated as

$\frac{\left( {D_{90} - D_{10}} \right)}{D_{50}}.$

RSD percent relative standard deviation, the standard deviation dividedby the mean of the series and multiplied by 100, also known as % CV.

FIGS. 1A and 1B show a nasal spray device 10 before engagement (FIG. 1A)and after engagement (FIG. 1B). The nasal spray bottle 10 is comprisedof a bottle 12 into which the calcitonin formulation is placed, and anactuator 14, which when actuated or engage forces a spray plume, 16, ofthe calcitonin out of the spray bottle, 12, through the actuator, 14. Aspray pattern is determined by taking a photograph of a cross-section ofthe spray plume 16 above a predetermined height, 18, of the plume. Thespray plume also has angle of ejection, 20, as it leaves actuator, 14. Aspray pattern of spray plume 16 is shown on FIG. 2. Spray pattern 2, iselliptical and has a major axis, 24, and a minor axis 26.

The compositions of the present invention may of course also includeadditional ingredients, in particular components belonging to the classof conventional pharmaceutically applicable surfactants.

Preferably, the liquid pharmaceutical calcitonin composition of thepresent invention contains a pharmaceutically acceptable, a liquiddiluent or carrier for application to the nasal mucosa, most preferablyaqueous saline.

The calcitonin solutions of the present invention are formulated so asto permit administration via the nasal route. For this purpose they mayalso contain additional ingredients including, for example, ciliarystimulants such as caffeine.

Generally, for nasal administration a mildly acid pH is preferred.Preferably the calcitonin solutions of the present invention will have apH of from 3 to 4, more preferably about 3.5. Adjustment of the pH isachieved by addition of an appropriate acid, such as hydrochloric acid.

The calcitonin solutions of the present invention should also possess anappropriate isotonicity and viscosity. Preferably, they have an osmoticpressure of from about 260 to about 380 mOsm/liter. Desired viscosityfor the nasal spray is preferably less than 0.98 cP.

The amount of calcitonin to be administered according to the method ofthe present invention will depend upon the particular calcitonin chosen,the condition treated, the desired frequency of administration and theeffect desired. Generally the concentration of calcitonin in solutionshould be about 2200 International Units (LU.) per ml. If 0.09 mL isadministered per actuation, this administers 200 I.U. to the patient.The International Units are based upon a bioassay in comparison with theInternational Reference Preparation of calcitonin-salmon for Bioassay,distributed by the National Institute of Biologic Standards and Control.

For the purposes of nasal administration, the calcitonin solutions ofthe present invention will be placed in a nasal applicator device.Suitable applicators are known in the art and include those adapted foradministration of liquid compositions to the nasal mucosa in drop orspray form. Since dosing with calcitonins should be as accuratelycontrolled as possible use of spray applicators for which theadministered quantity is susceptible to precise regulation willgenerally be preferred. Suitable administrators include atomizingdevices such as pump-atomizers and aerosol dispensers. The atomizingdevice will be provided with an appropriate spray adaptor allowingdelivery of the calcitonin solution to the nasal mucosa.

EXAMPLE 1 Preparation of Salmon Calcitonin Solution

A 1200 gram batch of the preferred calcitonin solution of the presentinvention was prepared according to the following procedure and wascomprised of the following ingredients.

TABLE 1 Weight per 1200 Ingredient Name % Weight/Weight gram BatchChlorobutanol anhydrous, NF   0.25% 3.00 Sodium Chloride, USP  0.85 10.2Salmon Calcitonin, EP -   0.0355 0.426 Potency of 6236 IU/mg 1%Hydrochloric Acid, NF Added as needed to adjust pH to 3.5 PurifiedWater, USP 98.86 1186.32 Nitrogen, NF

Procedure

Into a 3 Q stainless steel beaker was placed 1186.32 grams of water andthe beaker was covered with parafilm and the water was purged withnitrogen, NF and stirred. With continuous stirring and purging withnitrogen, 100 grams of chlorobutanol, (Spectrum Chemicals & LaboratorySupplies, Inc., Gardena, Calif.) was added to the water. Into thesolution was then added 10.2 g of sodium chloride (Mallinckrodt, Inc.St. Louis, Mo.). After the sodium chloride was dissolved, the oxygencontent was determined, and the solution was further purged withnitrogen until the oxygen content was less than 5%. Into the solutionwas added 0.426 g of calcitonin, EP (BACHEM California, Inc, Gardena,Calif.). Into the solution was added 1% HC1 until the pH of the solutionwas adjusted to 3.5. The weight of the solution was determined and asufficient amount of water was added to bring the weight of the solutionto 1200 g. The oxygen content was again determined, and the solution wasfurther purged with nitrogen until the oxygen content of the solutionwas less than 5% by volume.

EXAMPLE 2

This example describes a pharmaceutical composition product comprisingan aqueous solution formulation of salmon calcitonin at a concentrationsufficient to produce therapeutically effective plasma concentrationsand an actuator to produce an aerosol of said solution, wherein thespray pattern ellipticity ratio of said aerosol is between 1.00 and 1.40when measured at a height of 30 cm distance from the actuator tip.

The volume of the aerosol can be between about 5 microliters and 1.0 ml,preferably between 20 and 200 microliters.

This test method describes the procedure for characterizing plumegeometry of the calcitonin nasal solution formulations using theSprayView NSP system. The plume geometry is characterized using aSprayView High Speed Optical Spray Characterization System (SprayViewNSP) with Integrated SprayView NSx actuation station (Image ThermEngineering, Inc., Sudbury, Mass.) according to the methods described inU.S. Pat. No. 6,665,421 and U.S. Patent Application Publication No.20030018416 published Jan. 23, 2003.

Using the formulation of table 1 the spray characterization and dropletsize of the formulation in both a 1 mL and a 3 mL bottle both having anasal Spray Pump w/Safety Clip, Pfeiffer SAP # 63385, which delivers adose of 0.1 mL per squirt and has a diptube length of 36.05 mm.

The droplet size data are shown in the following table.

Droplet Size for Nasal Spray Bottle and Pfeiffer SAP # 60548 % < 10 D₁₀D₅₀ D₉₀ Span micrometer 1 mL Salmon calcitonin 14.0 32.7 94.4 2.4 4.1

Below are listed the spray pattern results

Spray Pattern MajorAxis MinorAxis EllipticityRatio active 1 mL 31.2 mm27.4 mm 1.15

1-7. (canceled)
 8. A method for intranasal administration of calcitoninwhich comprises administering intranasally to an individual a solutionof calcitonin comprising calcitonin, only one preservative and a liquiddiluent or carrier solution suitable for application to the nasalmucosa, wherein the preservative is chlorobutanol at a concentrationequal to or greater than about 0.25% and less than about 0.4%weight/weight.